Usually a car lock is formed with a rotatable latch bolt or lock cylinder, generally referred to as a "coded" lock cylinder, which bolt or cylinder cooperates with a latch sleeve or lock sleeve which is stably mounted in the door or any other part of the vehicle. The latch bolt or lock cylinder is formed with several lock plates which become partly pressed out of the lock cylinder when the key is extracted from the cylinder, whereby said lock plates engage one or more axial slots of the latch sleeve thereby making it impossible to rotate the lock cylinder in relation to the latch sleeve. Only a key exclusively designed for the actual lock can be introduced in the lock cylinder. When such a key is introduced in the lock cylinder the lock plates become retracted into the lock cylinder, and said cylinder again can be rotated in relation to the latch sleeve. Said lock cylinder generally actuates a lock arm which releases some blocking means for the door etc, so that the door can be opened, the ingition can be switched on, the steering wheel can be rotated etc.
It is known that many locks of the above mentioned type can be opened in that a heavy screw driver or any other flat tool is introduced into the key hole and is rotated so strongly that the lock plates of the lock cylinder become broken off, whereby the lock cylinder can be rotated in relation to the lock sleeve or latch sleeve, and the door can be opened, the steering wheel can be rotated, the iginition can be switched on etc., an operation which is, of course, not intended and acceptable.